Container closure

ABSTRACT

A sealing closure and method of applying it to circular opentop, thin-wall containers of glass or plastic is disclosed. The closure, formed of plastically deformable material such as thin sheet metal includes a first substantially flat circular portion having a depending cylindrical skirt portion and a radially outwardly extending flat rim at the lower end of the skirt which is substantially parallel to the first portion. The cylindrical skirt adjacent to the rim is radially dimpled around the entire periphery. The closure is applied to containers having a bead on their outer surface adjacent the opening. It is first placed over the end of the container and a slight force axially of the container is applied to hold the first portion of the closure in sealing engagement with the end of the container while the rim is positioned below the container bead. While maintaining this first applied force, a radially compressive force is applied uniformly around the end of the cylindrical portion adjacent the rim to plastically reduce the inner diameter of the rim to substantially the outer diameter of the container adjacent the bead.

United States Patent [191 Garza et al.

[ Oct. 7, 1975 [54] CONTAINER CLOSURE [75] Inventors: Roberto Gavazos Garza; John R.

Martin, both of Monterrey, N.L., Mexico [73] Assignce: Vidriera Monterrey, S.A., Monterrey, N. L., Mexico 22 Filed: May 31, 1974 [21] App]. No.: 475,120

[52] US. Cl 215/328; 215/328 [51] Int. CI. B6SD 41/10; B65D 41/12; B65D 41/40 [58] Field of Search 215/326, 327, 328

[56] References Cited UNITED STATES PATENTS 3,169,655 2/1965 Little 215/328 Primary ExaminerGeorge T. Hall Attorney, Agent, or Firm-Kemon, Palmer & Estabrook [57] ABSTRACT A sealing closure and method of applying it to circular open-top, thin-wall containers of glass or plastic is disclosed. The closure, formed of plastically deformable material such as thin sheet metal includes a first substantially flat circular portion having a depending cylindrical skirt portion and a radially outwardly extending flat rim at the lower end of the skirt which is substantially parallel to the first portion. The cylindrical skirt adjacent to the rim is radially dimpled around the entire periphery.

The closure is applied to containers having a head on their outer surface adjacent the opening. It is first placed over the end of the container and a slight force axially of the container is applied to hold the first portion of the closure in sealing engagement with the end of the container while the rim is positioned below the container bead. While maintaining this first applied force, a radially compressive force is applied uniformly around the end of the cylindrical portion adjacent the rim to plastically reduce the inner diameter of the rim to substantially the outer diameter of the container adjacent the bead.

1 Claim, 5 Drawing Figures CONTAINER CLOSURE BACKGROUND O THEJiNi j/E TION The closure of the to the invention is somewhat similar in appearance to a crown cap closure such as those conventionally employed on soft drinkbott'les and the like. In attempting to apply the conventional crown closure sealing techniques to thin-walled wide mouth glass or plastic jars such as baby food jars and the like, difficulty has been experienced .due the high mechanical an elastomeric gasket retained n the skirt portion of I the closure so thatit may be eased overthe bead adjacent the container opening without breaking the container. This of course addsto the expense of the closures and it would accordingly be desireableto be able to employ very thin-walledclosures generally of the crown type provided'the problemof container breakage during the closing of the containers can be solved.

' BRIEF S MMAR IOFKTHEINVENTION The-present invention provides what may be characterized as a somewhat-modified form a crown closure which can be employed to seal wide-mouthed, thinsectioned jars such as baby food jars andthe like without the need for sufficient force to endanger the integrity of the container being closed. A closure in accordance with the present invention is formed of thin sheet stock capable of plastic deformation and having a first substantially flat circular portion, the inner surface of which preferrably carries a plastisol coating to sealing engage the end of the container. A cylindrical skirt portion depends from the first circular portion and terminates in a radially outwardly extending flat rim. That portion of the skirt adjacent the rim is dimpled radially around its entire periphery. The containers with which the closure of the present invention are used include at least an upper cylindrical portion having a radially outwardly extending bead adjacent the end thereof. The closure is placed over the end of the container with the plastisol coating engaging the end of the container and with the rim of the closure positioned below and adjacent to the container bead. While applying only enough force axially to maintain a seal between the coating and the container a radially compressive force is then applied uniformly around the juncture of the rim and skirt portions. This plastically reduces the internal diameter of the closure to substantially that of the outer diameter of the container adjacent the bead and increases the thickness of the rim portion. This results in a sealed container, the closure of which can be removed with a tool as shown in my copending application, Ser. No. 475,121 filed May 31, 1974 which will stretch the rim portion past its yield point without deforming the sealing portion of the closure. When the diameter of the rim is greater than the diameter of the bead, the closure may then be manually lifted from the container, the contents partially used and the closure then replaced on the container to function as a dust cover while the container is stored in an ice box or the like for the remainder of the day until the balance of the contents is used.

' OFTIPIEFDRAWINGS FIG. 1 is'a'top'plan view: of a closure in accordance with the present invention;

- FIG. 2-isa side elevation of the closure of FIG. 1;

FIG. 3 shows a side elevation in section with the closure placed over the end of a container to be sealed and prior to the sealing operation; FIG. 4 is a view similar to FIG. 3 showing the clo siire in sealed position on a container; and

1 1G1 5 shows an op'e' ner tool to remove the closiir'e from a 'container without damagingt'he sealing portion.

.DETAILED DESCRIPTION OF, THE DRAWINGS As shown in FIGS. 1 and 2, the closure ofthe present inventionis formed of thin flat shee t'stock 'of plastic ally deformable material such as "metal and includes an upper circular portion 10. Dependingfrom the circular portion 10 is a substantially cylindrical skirt portio'n 12 which terminates in a plain flat"outwardly extending rim 14. The skirt portion 12 atits junction with the rim 14 is dimpled around On'the'under 'sideof circular portion 10 of the'clo sure a plastisol coating 18 is preferrably employed to facilitate the formation of a gas and liquidtight seal between the closure and'tlie end of 'the container. Such coatings are commonly used in'this artand no furtherdes'cription thereof is believed necessary, except to say that preferrably the coating is thermo-plastic sothat if applied'to a warm contain'erfthe "coating i's softened sufficiently to ensure a perfect seal during the closure applying process. I i

As shown in FIGS. 3 and 4, containers 30 to which the closures of the present invention are applicable include at least an upper cylindrical portion 32 having an outwardly extending bead 34 adjacent the end thereof. As commonly produced for the baby food market, such containers are blow-molded and are so thin incross section that they would not withstand the forces involved in applying a conventional crown seal. The inventor here has discovered, however, that such container's are surprisingly strong under radially applied compression loading providing the loading is substantially uniform around the periphery of the container. In fact, for a given cross section, such containers have been found to be stronger in compressive loading than steel.

In order to apply the closure of the present invention to a container of this type, the closure is first placed over the end of the filled vessel as indicated in FIG. 3. When so positioned, the rim is below the bead of the container when the inner coating is in contact with the end of the container. Starting in this position, an axial force is applied which is just sufficient to effect a seal between the end of the container and the coating on the inner surface of the closure. It should be noted that this force is very greatly less than that conventionally employed in pressing a conventional crown seal into place over the end, for example, of a thick-walled soft drink bottle. While maintaining the application of this mild axial force, a radially inwardly acting compressive force F is applied to the juncture of the rim and skirt portions of the closure as indicated generally by the arrows in FIGS. 3 and 4. This is accomplished by means of a multi-fingered collet like structure, the inner end of the fingers of the collet having almost sharp edges.

its entire periphery'as shown at The thin wall container is able to sustain a sufficient uniformly radially applied compressive loading to plastically reduce the inner diameter of the. rim portion of the closure to substantially the outer diameter of the cylindrical portionof the container andthis results in a slight increase in the thickness ofv the rim portion because under such plastic deformation, the metal has to move in some way.

The foregoing description should suffice to enable those skilled in thisart to understand the basic and fundamental differences in both the structure of the closureand the manner of applying it to a container over the conventional crown cap applying techniques. In the conventional crown cap, there is merely a deflection of the corrugated portions of the skirt to force them to 'underlie the bead of thecontainereNo actual plastic flow of the metal is involved and such closures may be easily removed by simply prying the corrugations outwardly. In order toremove the closures of the present invention, however, and particularly to remove them without disturbing the configuration of the sealing surfaces of the closure, it is necessary to emply a special tool which will stress the rim portion of the closure in hoop tension beyond its yield point until the diameter of the rim por tion is larger than the external diameter of the container bead. The thus plastically deformed closure may then be manually lifted off the container, the contents partially used inthe home and the closure may then be replaced on the open ended containen'not as a fluid and pressure tight seal, but nevertheless in a dust tight seal so that the container and the remaining contents may be stored in the refrigerator until later in the day when the remainder of the contents can be used.

By adopting the principles of the closure and method of applying as taught in this disclosure, closures of very thin'material may be utilized at substantial savings in material costs- While preferred embodiments have been herein cylindrical portion with a radially outwardly extending bead adjacent the open end of the container, said closure being of plastically deformable material and comprising:

a substantially plain circular portion of a diameter to sealingly engage the open top of the container; a cylindrical skirtportion depending from said circular portion;

. a flat rim extending radially outwardly from that end of said skirt portion remote from said first portion and at substantially to said skirt portion;

said skirt portion having a series of corrugations therein adjacent said rim, said closure being applied to a container by radial compression applied to the junction of said rim and said skirt to increase the thickness of metal in said rim and reduce the inside diameter of said rim by an amount to prevent removal from the container without stretching said rim in hoop tension beyond its yield point to permit free removal over the bead of the container. 

1. A closure cap for open top glass or plastic containers of thin wall construction having at least an upper cylindrical portion with a radially outwardly extending bead adjacent the open end of the container, said closure being of plastically deformable material and comprising: a substantially plain circular portion of a diameter to sealingly engage the open top of the container; a cylindrical skirt portion depending from said circular portion; a flat rim extending radially outwardly from that end of said skirt portion remote from said first portion and at substantially 90* to said skirt portion; said skirt portion having a series of corrugations therein adjacent said rim, said closure being applied to a container by radial compression applied to the junction of said rim and said skirt to increase the thickness of metal in said rim and reduce the inside diameter of said rim by an amount to prevent removal from the container without stretching said rim in hoop tension beyond its yield point to permit free removal over the bead of the container. 